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Differential D21201

[libcxxabi] Don't check gcc_s when building with libunwind
AbandonedPublic

Authored by Eugene.Zelenko on Jun 9 2016, 2:38 PM.

Details

Reviewers
mclow.lists
compnerd
EricWF

Diff Detail

Repository
rL LLVM

Event Timeline

Eugene.Zelenko updated this revision to Diff 60240.Jun 9 2016, 2:38 PM
Eugene.Zelenko retitled this revision from to [libcxxabi] Don't check gcc_s when building with libunwind.
Eugene.Zelenko updated this object.
Eugene.Zelenko added reviewers: EricWF, mclow.lists, compnerd.
Eugene.Zelenko set the repository for this revision to rL LLVM.
Eugene.Zelenko added a subscriber: llvm-commits.
compnerd requested changes to this revision.Jun 9 2016, 5:49 PM
compnerd edited edge metadata.

Unfortunately, __gcc_personality_v0 is not provided by libc as it should, but rather the compiler builtins. Using the LLVM unwinder does not guarantee that we are using clang_rt.builtins rather than libgcc. Changing this to check if we are using -rtlib=compiler-rt seems much more reasonable.

But, otherwise, this is a great idea.

This revision now requires changes to proceed.Jun 9 2016, 5:49 PM
Eugene.Zelenko added a comment.Jun 9 2016, 6:11 PM

Looks like -rtlib is not mentioned in libcxxabi at all. I build stage 1 LLVM/Clang with compiler-rt, so dependency should be satisfied, but I don't know enough details, so will be good idea if somebody more knowledgeable will take over this improvement.

Eugene.Zelenko abandoned this revision.Jul 15 2016, 10:31 AM

Obsoleted by Saleem work.

Revision Contents

PathSize
cmake/
4 lines

Diff 60240

cmake/config-ix.cmake

Context not available.
check_library_exists(c fopen "" LIBCXXABI_HAS_C_LIB) check_library_exists(c fopen "" LIBCXXABI_HAS_C_LIB)
check_library_exists(dl dladdr "" LIBCXXABI_HAS_DL_LIB) check_library_exists(dl dladdr "" LIBCXXABI_HAS_DL_LIB)
check_library_exists(pthread pthread_once "" LIBCXXABI_HAS_PTHREAD_LIB) check_library_exists(pthread pthread_once "" LIBCXXABI_HAS_PTHREAD_LIB)
check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXXABI_HAS_GCC_S_LIB) if (NOT LIBCXXABI_USE_LLVM_UNWINDER)
check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXXABI_HAS_GCC_S_LIB)
endif()
check_library_exists(c __cxa_thread_atexit_impl "" check_library_exists(c __cxa_thread_atexit_impl ""
LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL) LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL)
Context not available.